Membrane Lid with Recessed Tab, and Container Incorporating Same

ABSTRACT

A membrane lid having a recessed ring pull tab. The membrane lids comprises a permanently deformable layer (e.g., metal foil or thin sheet metal) having a disk portion and a tab projecting from the outer periphery of the disk portion. The tab is folded back onto the upper surface of the disk portion. A region of the disk portion underlying the folded-back tab defines a depression and the tab is folded back such that it is recessed within the depression. A sealing material is provided on the lower surface of the membrane lid for sealing the lid to a metal ring of a container.

BACKGROUND OF THE INVENTION

The invention relates to containers having a metal ring affixed to thetop end of the container so as to define an annular surface thatencircles the top opening of the container and to which a flexiblemembrane closure or lid is sealed to initially seal the container. Suchmembrane lids often have a tab that can be grasped and pulled tofacilitate peeling the membrane lid from the metal ring.

The tabs on such membrane lids represent potential difficulties duringhandling of the membrane lids by automated machinery. The tabs mayinitially lie flat against the upper surface of the membrane lids, buthandling can cause the tabs inadvertently to be lifted and consequentlythe tabs can get caught in the machinery and cause a jam or can get tornoff.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses this problem by providing a membrane lidhaving a recessed ring pull tab. The membrane lid comprises apermanently deformable layer (e.g., metal foil or thin sheet metal)having a disk portion and a tab projecting from the outer periphery ofthe disk portion. The tab is folded back onto the upper surface of thedisk portion. A region of the disk portion underlying the folded-backtab defines a depression and the tab is folded back such that it isrecessed within the depression. A sealing material is provided on thelower surface of the membrane lid for sealing the lid to a metal ring ofa container.

The membrane lid in one embodiment comprises a deformable layer ofmetal, and a sealant layer joined to a lower surface of the disk portionof the deformable layer. The tab does not have the sealant layer. Thedisk portion and the tab comprise a single piece of metal, being formedby a process of die-cutting (or similar process) from a sheet of metal.

In accordance with one embodiment of the invention, an outer edge of thetab is rolled to provide a cut-resistant outer edge. The tabadvantageously is ring-shaped, defining a finger hole therethrough. Aninner edge of the hole in the tab is also rolled to provide acut-resistant inner edge.

The disk portion of the lid can have a non-smooth (e.g., dimpled,pebbled, or waffled) configuration, if desired or necessary in aparticular application. Alternatively, the disk portion can be smooth.

A container in accordance with one embodiment of the invention comprisesa container body having a side wall that terminates in a top edgecircumscribing an opening of the container body. A metal ring is seamedto the top edge of the container body. The metal ring includes anannular portion that extends radially inwardly from the container bodyand defines an upper surface. The metal ring has an inner edgecircumscribing an aperture through the metal ring for access to theinterior of the container body. A membrane lid is sealed to the uppersurface of the metal ring. The membrane lid has a configuration asdescribed above, including a depression and a tab folded back into thedepression.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 is a perspective view of a container in accordance with oneembodiment of the invention;

FIG. 2 is a view similar to FIG. 1, showing the membrane lid beingpeeled away from the metal ring;

FIG. 3 is a top elevation of a metal ring and membrane lid assembly inaccordance with one embodiment of the invention, for attachment to acontainer;

FIG. 4 is a magnified top elevation of the tab region of the membranelid; and

FIG. 5 is a cross-sectional view through the metal ring and membrane lidassembly.

DETAILED DESCRIPTION OF THE INVENTION

The present inventions now will be described more fully hereinafter withreference to the accompanying drawings in which some but not allembodiments of the inventions are shown. Indeed, these inventions may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

A container 10 in accordance with one embodiment of the invention isshown in FIGS. 1 and 2. The container comprises a container body 12having a side wall 14 that encircles the interior space in the containerbody. The side wall extends upwardly and terminates in a top edge 16that circumscribes a top opening of the container body. Affixed to thetop edge 16 of the container body is a metal ring 20. The metal ring canbe affixed by double-seaming, wherein an outer curled region 22 of themetal ring is rolled outwardly along with a flange formed on the topedge of the container body. Double-seaming processes are well known andhence do not require detailed description herein. The metal ringincludes an annular portion 24 that is generally planar and extendsradially inwardly from the curled region 22. The annular portion definesan upper surface to which a membrane lid 30 is sealed.

FIGS. 3 through 5 show the assembly of the metal ring 20 and membranelid 30 in greater detail. The inner edge 26 of the metal ring is curledor rolled under to reduce the likelihood of a person cutting himself orherself on the edge when inserting a hand into the container, such as toscoop out a quantity of powdered or granular product. The metal ring 20can comprise steel such as tin-plated steel. The steel can be eithercoated or uncoated.

The membrane lid 30 comprises a disk portion 32 and a tab 34. The term“disk portion” as used herein is not limited to circular shapes, butalso includes other shapes such as polygonal, elliptical, oval, and thelike. The disk portion is sized larger than the aperture defined by theinner edge 26 of the metal ring such that an outer peripheral area ofthe disk portion overlaps the annular portion 22 of the ring. This outerperipheral area is sealed to the annular portion of the ring toinitially seal the contents within the container. To access the contentsthe first time, the membrane lid is peeled from the metal ring anddiscarded. A separate plastic overcap 28 (FIG. 1) is typically suppliedfor redosing the container after the initial opening.

To aid in peeling off the membrane lid 30, the lid includes the tab 34,which can be grasped and pulled as shown in FIG. 2. The tab 34 isattached to the outer edge of the disk portion 32. The membrane lid asmanufactured and sealed to the metal ring 20 has the tab 34 folded backonto the upper surface of the disk portion 32 so that the tab lies flatagainst the disk portion. This is done to keep the tab in a positionthat will not interfere with handling of the lid by automated sealingmachinery that seals the lid to the metal ring. When a consumer desiresto open the container 10, he or she lifts the tab 34 upwardly away fromthe upper surface of the lid and pulls the tab generally upwardly andaway from the part of the metal ring nearest the tab's juncture with theouter edge of the lid, so as to peel the lid from the metal ring 20. Thetab advantageously is ring-shaped, having a finger hole 36 through whicha finger can be slipped to facilitate grasping and pulling the tab, asshown in FIG. 2.

In accordance with the invention, to further aid in keeping the tab inthe folded-back position during automated sealing, the disk portion 32of the membrane lid has a localized depression 40 created by deformingthe disk portion from its otherwise generally flat configuration. Thedepression 40 is located beneath the folded-back tab 34 and is sized inlength, width, and depth to be able to receive the tab so that the tabis recessed within the depression. Advantageously, in one embodiment,the tab is recessed in the depression 40 so that the tab does notproject above the upper surface of the disk portion 32 outside thedepression. This substantially reduces the likelihood of the tab beinginadvertently lifted from its folded-back position prior to or duringautomated sealing. Prematurely lifted tabs can get jammed in theautomated machinery or can get torn off by the machinery, making it muchmore difficult for the consumer to peel off the membrane lid, or causingthe metal ring and membrane lid assembly to be rejected and have to bescrapped.

The membrane lid comprises a permanently (i.e., plastically) deformablestructure. More particularly, in preferred embodiments of the invention,the membrane lid includes a deformable layer of metal such as aluminumor the like. The deformable layer can comprise a metal foil or thinsheet metal. The metal layer in some embodiments of the invention canhave a thickness of about 0.045 mm to about 0.120 mm (about 45 to 120microns), and more preferably about 0.060 to about 0.090 mm (about 60 to90 microns). The depression 40 is formed by plastically deforming themetal layer with suitable tooling.

The membrane lid 30 includes a sealing material 38 (FIG. 2) on its lowersurface for sealing the lid to the metal ring 20. The sealing materialcan comprise a heat-sealable material. Various heat-sealable materialsare known and can be used. Non-limiting examples of suitableheat-sealable materials include heat-sealable lacquers (e.g., based onvinyl chloride, vinyl acetate, or copolymers thereof), polypropylene,polyethylene, polyamide, ethylene vinyl acetate, ethyl methacrylate,ionomer resins, epoxy resins, and blends thereof.

The membrane lid 30 can include a protective coating on the uppersurface of the metal layer. The protective coating may be useful forpreventing the lid from sticking to the automated sealing tooling usedfor heat-sealing the lid to the metal ring. For example, a polyestercoating can be applied to the upper surface of the metal layer.

In one embodiment of the invention, the lid 30 has three layers: thedeformable metal layer of aluminum, a polyester coating on the uppersurface of the metal layer, and a coating 38 (FIG. 2) of vinylchloride/vinyl acetate copolymer on the lower surface of the metallayer.

The lid 30 can be manufactured from a sheet of the coated metal bydie-cutting a blank from the sheet, then deforming the blank to form thedepression 40, then folding the tab 34 back into the depression. Theblank has the disk portion 32 and the tab 34 projecting radiallyoutwardly from the disk portion, as a one-piece integral structure. Thetab can be further processed by suitable tooling to roll the outer edgeof the tab and to roll the inner edge of the finger hole 36 so as toform cut-resistant edges that are less likely to cut a consumer'sfinger. Once the tab is fully formed, it is folded back into thedepression 40.

The lid 30 can also include embossments (schematically indicated at 42)such as dimples or a waffle pattern for stiffening the lid. Theembossments are formed by suitable tooling after the blank has beendie-cut from the metal sheet material. The region of the depression 40preferably does not have embossments. Furthermore, the outer peripheralarea of the lid that is sealed to the metal ring preferably does notinclude embossments.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

1. A container, comprising: a container body having a side wall thatterminates in a top edge circumscribing an opening of the containerbody; a metal ring affixed to the top edge of the container body, themetal ring including an annular portion that extends radially inwardlyfrom the container body and defines an upper surface, the metal ringhaving an inner edge circumscribing an aperture through the metal ringfor access to an interior of the container body; and a membrane lidsealed to the upper surface of the metal ring, the membrane lidcomprising: a permanently deformable layer having a disk portion and atab projecting from an outer periphery of the disk portion, the tabbeing folded back onto an upper surface of the disk portion, a region ofthe disk portion underlying the folded-back tab comprising a depressionformed in the disk portion and the tab being folded back into thedepression such that the tab is recessed within the depression, themembrane lid further comprising a sealing material on a lower surface ofthe membrane lid for sealing the lid to the metal ring.
 2. The containerof claim 1, wherein the tab defines a finger hole therethrough.
 3. Thecontainer of claim 2, wherein an outer edge of the tab and an inner edgeof the finger hole are rolled to reduce the likelihood of a finger beingcut by the tab.
 4. The container of claim 1, wherein the deformablelayer of the membrane lid comprises a sheet of metal.
 5. The containerof claim 4, wherein the disk portion and the tab comprise integralportions of the sheet of metal.
 6. The container of claim 4, wherein thesheet of metal has a thickness of about 0.045 to 0.120 mm.
 7. Thecontainer of claim 4, wherein the sealing material of the membrane lidcomprises a sealant layer joined to a lower surface of the deformablelayer.
 8. The container of claim 7, wherein the sealant layer coverssubstantially the entire disk portion of the deformable layer.
 9. Thecontainer of claim 8, wherein the sealant layer also covers the tab. 10.The container of claim 1, wherein the sealing material comprises aheat-sealable material.
 11. A membrane lid for a container, comprising:a permanently deformable layer having a disk portion and a tabprojecting from an outer periphery of the disk portion, the tab beingfolded back onto an upper surface of the disk portion, a region of thedisk portion underlying the folded-back tab comprising a depressionformed in the disk portion and the tab being folded back into thedepression such that the tab is recessed within the depression; and asealing material on a lower surface of the membrane lid for sealing thelid to a container.
 12. The membrane lid of claim 11, wherein the tabdefines a finger hole therethrough.
 13. The membrane lid of claim 12,wherein an outer edge of the tab and an inner edge of the finger holeare rolled to reduce the likelihood of a finger being cut by the tab.14. The membrane lid of claim 11, wherein the deformable layer of themembrane lid comprises a sheet of metal.
 15. The membrane lid of claim14, wherein the disk portion and the tab comprise integral portions ofthe sheet of metal.
 16. The membrane lid of claim 14, wherein the sheetof metal has a thickness of about 0.045 to 0.120 mm.
 17. The membranelid of claim 14, wherein the sealing material of the membrane lidcomprises a sealant layer joined to a lower surface of the deformablelayer.
 18. The membrane lid of claim 17, wherein the sealant layercovers substantially the entire disk portion of the deformable layer.19. The membrane lid of claim 18, wherein the sealant layer also coversthe tab.
 20. The membrane lid of claim 11, wherein the sealing materialcomprises a heat-sealable material.
 21. The membrane lid of claim 11,further comprising a heat-resistant coating on an upper surface of thedeformable layer.
 22. The membrane lid of claim 11, wherein membrane lidis embossed with a pattern of deformed regions for enhancing stiffnessof the lid.
 23. The membrane lid of claim 22, wherein the depression isnon-embossed.